[ty] Preserve type context kind when propagating to nested expressions (#30280)
The `TypeContextKind` of a given `TypeContext` should be preserved when
propagated to a nested expression. For example, an upper bound `T:
Payload` does not provide a solver preference for gradual types, and so
should not provide a preference to any fields of the `TypedDict`:
```py
from typing import TypedDict, Any
class Payload(TypedDict):
value: int
def payload[T: Payload](value: T) -> T:
return value
def identity[T](value: T) -> T:
return value
def _(value: Any):
payload(reveal_type(identity(value))) # revealed: Any
payload({"value": reveal_type(identity(value))}) # main: int, now: Any
```
There are a few places where we are incorrectly constructing a
`TypeContext` with the default `TypeContextKind` instead of preserving
it from the outer `TypeContext`, which this PR fixes.
ruff
11272cf4 - [ty] Preserve type context kind when propagating to nested expressions (#30280)
